This research is the first component of a systematic study of selective families of lizards and will examine the relationship of lizard nerve fiber activity to certain anatomical structures of the basilar papilla. The specific objective of this proposal is to study the transduction processes in the inner ear of an Iguanid lizard. This will be accomplished by analyzing the discharge patterns of the primary auditory nerve fibers to a variety of acoustic stimuli and determining the tonotopic organization of the auditory nerve and papilla. The research will indicate the importance of the two types of tectorial structures found in the Anguid and Iguanid ear in determining the discharge patterns of auditory nerve fibers and will correlate differences in the anatomy of the Anguid and Iguanid ear with variations in the activity of the auditory nerve fibers. Both results are fundamental to understanding the cochlear transduction processes.